/**
 * @file MathUtil.cpp
 * @author  Aljosa Osep <aljosa.osep@gmail.com, Fletcher Dunn, Ian Parnberry>
 * @version 1.0
 *
 * @section LICENSE
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:

 *  1. Redistributions of source code must retain the above copyright notice, this list of
 *    conditions and the following disclaimer.

 *  2. Redistributions in binary form must reproduce the above copyright notice, this list
 *     of conditions and the following disclaimer in the documentation and/or other materials
 *     provided with the distribution.

 * THIS SOFTWARE IS PROVIDED BY <Aljosa Osep> ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL <Aljosa Osep>> OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of <Aljosa Osep>.
 *
 * @section DESCRIPTION
 *
 * MathUtil - math utility functions implementation
 * Based on examples from 3D Math Premier of Graphics and Games Development book
 * Original authors: Fletcher Dunn, Ian Parnberry. Thanks!
 */

#include "MathUtil.h"

//

/**
 * Wraps angle
 *
 * Wrap angle in range -pi ... pi by adding correct multiple of 2pi
 *
 * @param  An angle to wrap
 * @return Angle between -PI and PI
 */
extern float wrapPi(float theta) {
        theta += kPi;
        theta -= floor(theta * k1Over2Pi) * k2Pi;
        theta -= kPi;

        return theta;
}

/**
 * Safe acos
 *
 * Arcus cosinus, validates x first
 *
 * @param  x ... an value
 * @return Angle
 */
// Safe acos
extern float safeAcos(float x) {
    // check limits
    if (x <= -1.0f)
        return kPi;
    if (x >= 1.0f)
        return 0.0f;

    return acos(x);
}

/**
 * Sine Cosine
 *
 * Calculates both sinus and cosinus, returns value over reference
 *
 * @return Sinus and Cosinus over reference
 */
// Calculate both sine ans cosine of angle
extern void sinCos(float *retSin, float *retCos, float theta) {
    *retSin = sin(theta);
    *retCos = cos(theta);
}

// TODO: document for doxy
extern float Rad2Deg(float theta) {
    // Degrees = radians * (180 / PI)
    // 180 / PI = 57.295779579
    return theta * 57.295779579f;
}

extern float Deg2Rad(float theta) {
    // Radians = degrees * (PI / 180)
    // PI / 180 = 0.017453293
    return theta * 0.017453293f;
}

